I seriously love the book. For the Atheists, you are right it can be a bible. I personally have a hard time looking at ANYTHING as a bible, even the bible itself. I took more from Atlas Shrugged than almost any other book I have ever read and I have incorporated it into my lifestyle so I guess in a way it could be a bible.
I know the passage you are discussing with DiAnconia (I have read it numerous times lol). You are right, possibly one of the most powerful passages.
“And this I believe: that the free, exploring mind of the individual human is the most valuable thing in the world. And this I would fight for: the freedom of the mind to take any direction it wishes, undirected." Steinbeck